This invention relates to water cooled furnace doors and in particular to such a door for use in a slagging furnace.
When supplying an access door for a furnace, it must of course, be able to tolerate high furnace temperatures. Certain furnaces including most of in which coal is burned operate under slagging conditions. Molten ash forms on the walls on the furnace at least at the general location of the burner elevation. This slag can cause erosion and corrosion of refractory material located in the slagging zone of the furnace.
Various furnace door constructions such as those shown in U.S. Pat. No. 2,534,747 (H. W. Wilson et al) and U.S. Pat. No. 2,547,204 (R. B. Groetzinger) have cooled the refractory portion of a furnace door by routing water cooled tubes through the refractory. Such designs make it possible for the doors to operate for longer times at higher furnace temperatures.
In a slagging furnace however, it has been found that the molten slag tends to erode and corrode the refractory material leading to an unacceptable frequency of repair or replacement. Accordingly, there is a need for a door which will operate satisfactorily for extended periods in such a slagging environment.